Liquid level regulation apparatus



J. W, 1939. A. J. WEINIG I LIQUID LEVEL REGULATION APPARATUS Filed March1, 1935 2 Sheets-Sheet l INVENTOR. ARTHUR d. WE/N/G ATTORNEY.

Jan. 10, 1939.. A. .1. WEINIG LIQUID LEVEL REGULATION APPARATUS FiledMarch 1, 1935 2 Sheets-Sheet 2 INVENTOR.

ATTORNEY.

Patented Jan. 10, 1939 UNITED STATES PATENT OFFICE LIQUID LEVELREGULATION APPARATUS rado Application March 1, 1935, Serial No. 8,946

8 Claims My invention relates to a means for regulating the level of abody of liquid, and more particularly to the liquid level regulation ofa multicell flotation machine, subject to a continuous feed anddischarge.

It is an object of the present invention to provide a regulating devicewhich may be initially adjusted to establish a normal liquid level andwhich operates automatically thereafter to vary the rate of dischargefrom a liquid body in response to fluctuations in feed, to therebymaintain a substantially constant liquid level.

I-Ieretofore in the art, various regulating means have been employed. Anadjustable Weir is probably the most common form of level regulatingdevice for flotation machines at present in commercial usage. While weirregulation has worked very well in practice, it has a tendency topromote the deposit and building up of sediment,

20 particularly when treating gritty pulps, which results in cloggingthe machine.

Also, weir regulation is not responsive to minor fluctuations in theliquid level, and as a consequence, the elevation of the froth layerwith respect to the froth overflow is almost constantly changing, andfroth of varying quality is discharged across the overflow.

The desideratum in froth flotation operations is to maintain a frothlayer of uniform depth in order that a selective percentage only of thefroth may be removed and by maintaining the percentage removed constant,a concentrate of uniform quality is obtained.

Another object of my invention is to effect a removal of froth ofuniform quality in the flotation treatment by controllingthe liquidlevel.

Still another object of my invention is the provision of a dischargecontrol which is counterbalanced with respect to hydrostatic pressure in40 the liquid body, and which is actuated by any variationirom thebalance.

A further object of the invention is to provide a control device whichis simple and durable in construction, positiveand noiseless inoperation, and which is resistant to friction and corrosion.

Other objects of the invention reside in novel details of constructionand novel combinations and arrangements of parts as will more fullyappear in the course of the following description.

Referring to the drawings in the several views of which similar partshave been similarly des ignated,

Figure lis a front elevation, partially in sec.-

tion of a muti-cell flotation machine to which the present invention hasbeen applied,

Figure 2 is a section taken along the line 2-2, Figure 1,

Figure 3 is a plan view of the last two cells and discharge compartmentof the machine illustrated in Figure 1,

Figure 4 is an enlarged plan view of the regulating device of theflotation machine illustrated in Figure l, with a portion of a diaphragmbroken away to show the overflow passage, and

Figure 5 is a section taken along the line 55, Figure 4.

As illustrated in Figure 1, a flotation machine comprising a tank 6,divided by partitions 1 into a series of cells 8 is provided at one end,with a feed compartment 9, and at its opposite end with a dischargecompartment ID.

A froth overflow lip 12 extends along one side wall of the tank 6, and alaunder I3 beneath the lip l2 receives the overflowing froth. The wallof the tank 6 opposite the overflow lip I2 is bent inwardly at M belowthe normal froth level and acts as a froth-crowder.

A header l5 connected with a source of compressed air (not shown)extends along a side of the tank 6.

Each cell 8 is provided with an air inlet is beneath an impeller I1, anda flexible conduit l8 delivers air to the inlet from the header 15. Ifdesired, regulating valves l9 may be provided for varying the quantityof air supplied to each cell.

A baiiie-element is disposed in each cell above the impeller, and a grid2| extending across the cell above the baffie-element 20 defines zonesof agitation and separation in each cell.

The partitions 1 have openings 22 neartheir lower ends providingpassages which permit the direct flow of material under treatment fromcell to cell, and are particularly effective in preventing excessiveaccumulation of non-floated gangue in the respective cells.

A rotary froth skimmer or paddle 23 is mounted near the overflow lip l2of each cell and moves the froth toward the overflow lip.

A convenient driving assembly for the moving parts of the machine hasbeen illustrated in Figures 1, 2 and 3.

The impellers l! are mounted for rotation on shafts 24 depending from asuperstructure 25 supported above the tank 6. Pulleys 26 are mounted onthe upper ends of shafts 24 and connected by belts 21 or other suitablemeans with motors 28 on the superstructure.

A lengthwise of the tank 6. One end of shaft 29 extends beyond the tank,and a pulley 30 is mounted on the extended end of the shaft.

The pulley 30 is driven by a motor 28, through the intermediary of abelt 3|, or any other suitable means, and reduction gearing contained.

in a housing 32 on superstructure 25 in operative connection with one ofthe motors. Since the driving assembly is of conventional construction,detailed description of its component parts appears unnecessary. It willalso be understood that while the machine illustrated is a motordriventype, the invention is operative regardless of what sort of drivingmechanism is employed.

The only tailings outlet for the machine illustrated in Figure 1 isprovided by an orifice 33 in an end Wall 34 of the tank 6 opening intothe discharge compartment Ill.

The compartment H] which is open at its upper end, preferably consistsof side walls 35 fitted on the end wall 34 of tank 6, a bottom 36 havingan outlet 31, and an end wall 38.

In its lower portion, end wall 38 is apertured to provide a serviceentrance, which is normally covered by a removable plate 39, andbolt-holes 40 are provided in its upper surface for a purposehereinafter explained.

An elbow 4| fitted over the orifice 33 serves as an upwardly rangingconduit for tailings discharging through the orifice. A series of radialears 42 extend from the upper wall of elbow 4|, and the upper end of theconduit is smoothed to provide a valve seat 43.

A valve 44 movable relative to seat 43 controls the discharge from theconduit 4|. This valve comprises a flexible diaphragm 45 held betweenplates 46 mounted on a rod 41. At its circumferential edge, thediaphragm 45 is clamped between a pair of rings 48, fastened on ears 42.One or more spacer rings 49 may be mounted on ears 42 to elevate theclamping rings 48 and thereby the diaphragm 45 relative to valve seat43, which is the tailings overflow of the machine.

The rod 41 depends from a block 56 pivotally carried betweenbifurcations 5| of a lever 52. The rod 41 is threaded at 53 andadjusting nuts 54 bearing against block 5!) permit adjustments of therod relative to the block.

One end of lever 52 overhangs the tank and a float 55 mounted on a rod56 depending from the overhanging end of the lever 52 is disposed withinthe tank 6. The rod 56 is also threaded at 51 and nuts 58 bearingagainst lever 52 permit its lengthwise adjustment for predetermining theliquid level in the tank.

. The lever is flexibly supported on end wall 36 of the dischargecompartment by means of a strip 59 of flexible material, preferablyrubber, which is held between two plates 69 bolted on end wall 38.

Slots 6| in plates 60 are disposed to register with bolt-holes 46, andbolts 62 inserted through bolt-holes 40 and slots 6| serve to hold thestrip against movement relative to the plates by tightening of nuts 63.

The slots 6| permit movement of the plates 60 relative to the end-wall38, and by this means, the degree of flexibility of strip 59 may bevaried, as an increase in the distance between the ends of plates60and'lever 52 will increase the flexibility of strip 59, and a decreasein the distance between the plates and the lever will decrease itsflexibility.

A seat 64 on rod 41 supports an upright pin 65 and provides a rest forremovable weights 66. The discharge end of conduit 4| is at an elevationconsiderably lower than the normal liquid level as determined by theposition of the float 55, and as a result, the diaphragm 45 is subjectedto considerable hydrostatic pressure.

The combined weight of the lever 52, rod 41 and weights 66 is directedagainst the diaphragm 45 to counterbalancethe hydrostatic pressure inthe conduit 4|, so that the volme of liquid discharging therefrom isequivalent to the volume of feed entering the tank at the inlet 9.

Once this balance has been established by placing the proper amount ofweight on seat 64, and by minor adjustment of rod 41, the control willoperate automatically thereafter. The lever 52 is also apertured at 61to permit suspension of an additional weight, if such an arrangement isrequired to facilitate balancing of the control.

Variations in feed, however slight, are communicated to the float 55 andthence to the diaphragm 45 through the lever 52 and rod 41. If more thana normal amount of feed enters the tank, float 55 rises, causing rod 41to move diaphragm 45 farther away from the seat 43, and if the feed issubnormal, the float descends in the tank and rod 41 moves diaphragm 45toward or against seat 43.

In Figures 1 and 5, the elbow 4| has been illustrated as having atailings discharge spout 16 in its lower portion. Whenever the coarsesands do not rise and discharge freely across valve seat 43, it isadvisable to maintain this spout open, to prevent any excessiveaccumulation of tailings at the discharge outlet.

With many pulps, however, the coarse sands will readily pass through thevalve, and under such conditions the spout 19 may be plugged in anyconvenient manner, a screw cap for example, and all tailings will bedischarged across valve seat 43.

It will be understood that the machine will operate substantially thesame whatever arrangement is employed. When spout 19 is open, the valve45 is not opened as wide as it would be with the spout closed, but whenthe initial regulation is effected, the operation is automaticthereafter.

From the foregoing it is apparent that a normal liquid level having oncebeen established, the control will vary the effective size of thedischarge orifice so that no more liquid can escape from the tank thanis fed into the same, and when the spout 19 is closed, this conditionexists even though the feed to the machine is entirely stopped.

This results in maintaining a uniform liquid level in the tank, and as aconsequence, the froth layer is not subject to variations in elevationrelative to the overflow lip l2. In this way it is possible to retain inthe machine, froth at a selective depth below the top of the layer andto discharge across the overfiow only concentrate of uniform quality.

The provision of a flexible mounting for the lever 52 insures noiselessoperation, as well as resistance to friction and corrosion due toinherent qualities of the material from which the strip 59 is made.

In this connection however, it will be understood that the diaphragmvalve of the present invention is readily applicable to flotationmachines of all types, and may be used to regulate the level in one ormore cells of the machine.

tive cell to control the level in such cell.

In the flotation of ores, it is frequently desirable to employ a numberof cells for roughing and the remaining cells of the same machine for acleaning operation. In such an operation it may be necessary to have theliquid level in one series of cells at a difierent elevation than thelevel in the remaining cells of the machine. For such requirements, onediaphragm valve may be used to regulate the level of the rougher cells,and another diaphragm valve may be used to control the level in thecleaning cells.

These applications of the invention will be readily understood by anyoneskilled in the art, and detailed description and illustration of thesame appears unnecessary.

Features described but not claimed herein have been made the subjectmatter of claims in my copending application, Serial No. 105,280, filedOctober 12, 1936, for Flotation process.

Changes and modifications may be availed of within the spirit and scopeof the invention as defined in the hereunto appended claims.

What I claim and desire to secure by Letters Patent is:

l. The combination with a tank having a discharge compartment and adischarge outlet in said compartment providing a valve seat, of adischarge control device comprising a lever, a float depending from thelever in the tank, a flexible fulcrum for the lever on a Wall of thecompartment, a rod on the lever, a diaphragm on the rod, and means forholding the diaphragm against lateral movement relative to the valveseat.

2. The combination with a tank having a discharge compartment and adischarge outlet in said compartment providing a valve seat, of adischarge control device comprising a lever, a float depending from thelever in the tank, clamping plates on a wall of the compartment, aflexible fulcrum for the lever held between the clamping plates, a rodon the lever, a diaphragm on the rod, and means for holding thediaphragm against lateral movement relative to the valve seat.

3. The combination with a tank having a discharge compartment and adischarge outlet in said compartment providing a valve seat, of adischarge control device comprising a lever, a float depending from thelever in the tank,

clamping plates on a wall of the compartment,

a flexible fulcrum for the lever held between the clamping plates, a rodon the lever, a diaphragm on the rod, and means for holding thediaphragm against lateral movement relative to the valve seat, theclamping plates being adjustable relative to the lever for varying thedegree of flexibility of the lever.

4. The combination with a tank having a discharge compartment and adischarge outlet in said compartment providing a valve seat, of adischarge control device comprising a lever, a float depending from thelever in the tank, complementary clamping plates having alined slots, aflexible fulcrum for the lever held between the clamping plates,adjustable means extending through the slots for fastening the plates inselective positions on a wall of the compartment, a rod on the lever, adiaphragm on the rod, and means for holding the diaphragm againstlateral movement relative to the valve seat.

5. Flotation apparatus comprising a tank having a feed inlet and havinga discharge outlet providing a valve seat, and. a control device forregulating the discharge of material from the tank, comprising a lever,a float carried by the lever and disposed within the tank, a flexiblefulcrum for the lever, a rod on the lever, a diaphragm on the rod, andmeans holding the diaphragm in operative connection with the dischargeoutlet.

6. Flotation apparatus comprising a tank having a feed inlet and havinga discharge outlet providing a valve seat, and a control device forregulating the discharge of material from the tank, comprising a lever,a float carried by the lever and disposed within the tank, a flexiblefulcrum for the lever, means for varying the de-- gree of flexibility ofthe fulcrum, a rod on the lever, a diaphragm on the rod, and meansholding the diaphragm in operative connection with the discharge outlet.

7. In level-regulating apparatus, the combination with a diaphragmvalve, of lever-mechanism for flexing the diaphragm, including a lever,and a flexible fulcrum held on a rigid support in supporting relation tothe lever.

8. In level-regulating apparatus, the combination with a diaphragmvalve, of lever-mechanism for flexing the diaphragm, including a lever,rigid clamping plates supported adjacent the lever,

III

and a flexible fulcrum held between the clamp- 55

